Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. The secondary seal ring is disposed between and contacts the primary seal assembly and housing structure so as to form a bore seal and a face seal therewith.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove may contain a pocket. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove is an axial bore groove extending perpendicularly to a longitudinal axis of the seal ring segment in fluid communication with the dead end circumferential groove so as to direct fluid flow generated from a rotating shaft into the dead end circumferential groove.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. Additional grooves are contained on the shaft-side face of each sealing ring segment. The additional grooves direct and create pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. The secondary seal ring is disposed between and contacts the primary seal assembly and housing structure so as to form a bore seal and a face seal therewith.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. The secondary seal ring is disposed between and contacts the primary seal assembly and housing structure so as to form a bore seal and a face seal therewith.

Abstract: A double dam reverse pressure face seal assembly for use in the turbomachine having a tunnel extending through the machine for high pressure air passage therein during normal machine operating has a mating ring positioned annularly respecting the tunnel for flow of lubricating oil generally outwardly through passageways in the ring and a sealing member biased against an interface surface of the mating ring, the sealing member including a first dam presenting a first contact face to the interface surface of the mating ring, a second dam integral with an outboard of the first dam, presenting a second contact face to the interface surface of the mating ring and a channel between the first and second dams for annularly downward flow of oil leaking inwardly past the second dam towards a channel exit.

Abstract: The present invention relates to a windback device and method of use to prevent lubricant from leaking from a lubricant sump. More specifically, the present invention is comprised of a windback device within a lubricant sump formed from the coupling of an annular sump housing, an annular fluid seal assembly, and a bearing. The annular housing substantially surrounds the runner to form a chamber. The seal assembly is coupled to a sump housing both of which are adapted to receive a rotatable runner such that a sealed chamber is formed around the runner. A plurality of inclined threads extend along an inner face of the windback device and are angled such that lubricant or fluid splashed from the rotating shaft is redirected away from a shaft seal element of the annular fluid seal and through leak off slots leading to the sump housing chamber.

Abstract: A circumferential film-riding seal operative in a gaseous or liquid environment about a rotating shaft is provided so that it is able to function with extended lifetime, low leakage, and a high-pressure difference thereacross. These characteristics are achieved by the employment of a segmented seal ring mounted in tandem with a floating load ring surrounding the rotating shaft. The seal ring has a bore surface thereon confronting the shaft, and the bore surface has a circumferential lift region located downstream of a circumferential bearing region. The bearing region has additional lift grooves either in the seal ring or in the shaft surface confronting the bearing region, together with feed grooves connecting the additional lift grooves, respectively, to a higher-pressure region adjacent the shaft.

Abstract: This invention discloses a completely different hydrodynamic gas seal configuration from both the Rayleigh bearing and other prior art. Instead of the shallow, wide, and short single pocket geometry for the Rayleigh bearing, and instead of the multiple depth grooves of the other prior art teachings, the hydrodynamic seal in this invention has a sealing face with lift pockets therein that are deep (normally in the range of about 0.010 inches to about 0.025 inches deep), narrow, long, multiple, coextensive, parallel, and single-depth. This invention incorporates the same basic hydraulic principle of generating pressure rise by the shearing gradient between the rotating shaft and stationary carbon elements, and therefore produces a force which is opposite in direction to the rubbing force generated by the ambient pressure drop across the seal. In this invention the forces are more evenly balanced across the axial face of the seal ring segments, thereby accommodating any conicity of the shaft race.

Abstract: A face seal is provided for a rotating shaft for sealing between a normally high pressure region and a normally lower pressure region, having a seal ring shaped to form a gap between the ring and a runner surface on the shaft, which gap converges in the direction of fluid flow and deliberately creates turbulent flow along the seal gap and sufficient clearance between the rotating runner and the seal ring to accommodate distortions in the seal ring which may occur over its lifetime. A servo system is coupled to the seal ring which moves the seal ring away from the runner during low pressure differences between the regions and which restores the sealing function along the seal gap when the pressure difference between the regions increases sufficiently.

Abstract: A seal structure is provided having a configuration with a very small seal gap between a relatively stationary seal member and a complementary surface on a movable (rotatable) member (such as a rotating shaft) adjacent to which the stationary seal member is mounted. The stationary seal member is movable toward and away from the movable seal member so as to vary the seal gap therebetween. The seal is effective in applications where an incompressible fluid is provided on the high pressure side of the stationary seal member so that leakage along the seal gap is of an incompressible fluid into a lower pressure region on the other side of the seal gap. A sealing dam is provided on the stationary seal member on its sealing face adjacent the low pressure end of the seal gap. A plurality of elongated pads are formed on the sealing surface of the stationary seal member on the high pressure side of the sealing dam, extending perpendicularly to the direction of leakage flow along the seal gap.

Abstract: A seal for sealing between a bidirectionally rotating shaft rotatable in the forward and reverse directions and having a sealing surface thereon located in a pressurized housing containing the shaft. A seal ring mounted in the housing for movement toward and away from the shaft sealing surface and having a high pressure side, a low pressure side, a seal face opposed to the shaft seal surface and an outer face remote from the seal face and exposed to the pressure in the housing. Resilient elements urge the seal ring toward the sealing surface of the shaft. Hydrodynamic elements in the form of a plurality of spaced recesses in the seal face of the seal ring and formed so as to produce negative hydrodynamic lift in the recess and urge the seal ring toward the sealing surface of the rotating shaft during forward rotation thereof.